/*
 * Copyright (c) 2006, Swedish Institute of Computer Science.
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. Neither the name of the Institute nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 *
 * This file is part of the uIP TCP/IP stack
 *
 * $Id: uip-neighbor.c,v 1.2 2006/06/12 08:00:30 adam Exp $
 */

/**
 * \file
 *         Database of link-local neighbors, used by IPv6 code and
 *         to be used by a future ARP code rewrite.
 * \author
 *         Adam Dunkels <adam@sics.se>
 */

#include "uip-neighbor.h"

#include <string.h>

#define MAX_TIME 128

#ifdef UIP_NEIGHBOR_CONF_ENTRIES
	#define ENTRIES UIP_NEIGHBOR_CONF_ENTRIES
#else /* UIP_NEIGHBOR_CONF_ENTRIES */
	#define ENTRIES 8
#endif /* UIP_NEIGHBOR_CONF_ENTRIES */

struct neighbor_entry {
	uip_ipaddr_t ipaddr;
	struct uip_neighbor_addr addr;
	u8_t time;
};
static struct neighbor_entry entries[ENTRIES];

/*---------------------------------------------------------------------------*/
void
uip_neighbor_init(void)
{
	int i;

	for(i = 0; i < ENTRIES; ++i) {
		entries[i].time = MAX_TIME;
	}
}
/*---------------------------------------------------------------------------*/
void
uip_neighbor_periodic(void)
{
	int i;

	for(i = 0; i < ENTRIES; ++i) {
		if(entries[i].time < MAX_TIME) {
			entries[i].time++;
		}
	}
}
/*---------------------------------------------------------------------------*/
void
uip_neighbor_add(uip_ipaddr_t ipaddr, struct uip_neighbor_addr* addr)
{
	int i, oldest;
	u8_t oldest_time;

	printf("Adding neighbor with link address %02x:%02x:%02x:%02x:%02x:%02x\n",
	       addr->addr.addr[0], addr->addr.addr[1], addr->addr.addr[2], addr->addr.addr[3],
	       addr->addr.addr[4], addr->addr.addr[5]);

	/* Find the first unused entry or the oldest used entry. */
	oldest_time = 0;
	oldest = 0;

	for(i = 0; i < ENTRIES; ++i) {
		if(entries[i].time == MAX_TIME) {
			oldest = i;
			break;
		}

		if(uip_ipaddr_cmp(entries[i].ipaddr, addr)) {
			oldest = i;
			break;
		}

		if(entries[i].time > oldest_time) {
			oldest = i;
			oldest_time = entries[i].time;
		}
	}

	/* Use the oldest or first free entry (either pointed to by the
	   "oldest" variable). */
	entries[oldest].time = 0;
	uip_ipaddr_copy(entries[oldest].ipaddr, ipaddr);
	memcpy(&entries[oldest].addr, addr, sizeof(struct uip_neighbor_addr));
}
/*---------------------------------------------------------------------------*/
static struct neighbor_entry*
find_entry(uip_ipaddr_t ipaddr)
{
	int i;

	for(i = 0; i < ENTRIES; ++i) {
		if(uip_ipaddr_cmp(entries[i].ipaddr, ipaddr)) {
			return &entries[i];
		}
	}

	return NULL;
}
/*---------------------------------------------------------------------------*/
void
uip_neighbor_update(uip_ipaddr_t ipaddr)
{
	struct neighbor_entry* e;

	e = find_entry(ipaddr);

	if(e != NULL) {
		e->time = 0;
	}
}
/*---------------------------------------------------------------------------*/
struct uip_neighbor_addr*
uip_neighbor_lookup(uip_ipaddr_t ipaddr)
{
	struct neighbor_entry* e;

	e = find_entry(ipaddr);

	if(e != NULL) {
		/*    printf("Lookup neighbor with link address %02x:%02x:%02x:%02x:%02x:%02x\n",
		   e->addr.addr.addr[0], e->addr.addr.addr[1], e->addr.addr.addr[2], e->addr.addr.addr[3],
		   e->addr.addr.addr[4], e->addr.addr.addr[5]);*/

		return &e->addr;
	}

	return NULL;
}
/*---------------------------------------------------------------------------*/
